Answer:
GIVEN :
Patti is using mental math to evaluate the expression (70 + 12.8 + 30) + 6.1
TO FIND :
The properties of operations allow Patti to simplify.
SOLUTION :
Given that Patti is using mental math to evaluate the expression (70 + 12.8 + 30) + 6.1.
Option d) She can use the commutative property to rewrite the expression as (70 + 30 + 12.8) + 6.1 is correct.
For :
Patti's expression is (70 + 12.8 + 30) + 6.1
By using the commutative property of addition
a+b=b+a
(70 + 12.8 + 30) + 6.1
= (70+30+12.8)+6.1 (here a=12.8 and b=30)
∴ the properties of operations allow Patti to take is the commutative property of addition.
Brianna's thinking is incorrect.
Expessions A, and C. are equivalent.
For C, you add 5x and x together (because they have the same variable) to get 6x - 4.
For A, you subtract 9x and 3x (because they have the same variable) to get 6x- 4.
B) 16 + (5 + 2) - 1
I don’t know what C is
